This thesis offers an excellent, comprehensive introduction to the physics of the quark–gluon plasma. It clearly explains the connection between theory and experiment, making the topic accessible to non-specialists in this field. The experimental work, which contributes significantly to our understanding of the quark–gluon plasma, is described in great detail. The results described in the final chapters of the thesis provide interesting new ideas about the connection between proton-proton and Pb-Pb collisions. Simone Schuchmann received the 'ALICE Thesis Award 2016' for this excellent work.
This thesis presents the first measurements of jets in relativistic heavy ion collisions as reported by the ATLAS Collaboration. These include the first direct observation of jet quenching through the observation of a centrality-dependent dijet asymmetry. Also, a series of jet suppression measurements are presented, which provide quantitative constraints on theoretical models of jet quenching. These results follow a detailed introduction to heavy ion physics with emphasis on the phenomenon of jet quenching and a comprehensive description of the ATLAS detector and its capabilities with regard to performing these measurements.
This unique volume contains the materials of the XXIXth International Workshop on High Energy Physics. The content of the volume is much wider than just high-energy physics and actually concerns all the most fundamental areas of modern physics research: high-energy physics proper, gravitation and cosmology. Presentations embrace both theory and experiment.
An introduction to the main ideas used in the physics of ultra-realistic heavy-ion collisions, this book covers topics such as hot and dense matter and the formation of the quark-gluon plasma in present and future heavy-ion experiments
This volume gathers the content of the courses held at the Third IDPASC School, which took place in San Martiño Pinario, Hospederia and Seminario Maior, in the city of Santiago de Compostela, Galiza, Spain, from January 21st to February 2nd, 2013. This school is the annual joint program of the International Doctorate Network in Particle Physics, Astrophysics, and Cosmology (IDPASC). The purpose of the school series is to present doctoral students from different universities and laboratories in Europe and beyond with a broad range of the latest results and current state of the art in the fields of Particle Physics, Astrophysics, and Cosmology, and to further introduce them to both the questions now posed by the potentials of physics and to challenges connected with current and future experiments – in particular, with the newly available energy ranges. Following these guidelines, the content of this third edition of the IDPASC School was jointly planned by the Academic Council and by the network’s International Committee, whose members ensure every year its timely formulation, keeping up with the constant evolution of these fields. The program covers a balanced range of the latest developments in these fields worldwide, with courses offered by internationally acknowledged physicists on the Basic Features of Hadronic Processes, Quantum Chromodynamics, Physics and Technology of ALICE, LHCb Physics-Parity Violation, the Higgs System in and beyond the Standard Model, Higgs Searches at the LHC, Theory and Experiments with Cosmic Rays, Numerical Methods and Data Analysis in Particle Physics, Theoretical Cosmology, and AdS/CFT Correspondence. Most of these courses were complemented by practical and discussion sessions.
The Large Hadron Collider (LHC) is the highest energy collider ever built. It resides near Geneva in a tunnel 3.8m wide, with a circumference of 26.7km, which was excavated in 1983-1988 to initially house the electron-positron collider LEP. The LHC was approved in 1995, and it took until 2010 for reliable operation. By now, a larger set of larger integrated luminosities have been accumulated for physics analyses in the four collider experiments: ATLAS, CMS, LHCb and ALICE.The LHC operates with an extended cryogenic plant, using a multi-stage injection system comprising the PS and SPS accelerators (still in use for particle physics experiments at lower energies). The beams are guided by 1232 superconducting high field dipole magnets.Intense works are underway in preparation of the High Luminosity LHC, aimed at upgrading the LHC and detectors for collecting ten times more luminosity, and extending the collider life to the early 2040's. So far, the (HL-)LHC project represents a cumulation of around one hundred thousand person-years of innovative work by technicians, engineers, and physicists from all over the world; probably the largest scientific effort ever in the history of humanity. The book is driven by the realisation of the unique value of this accelerator complex and by the recognition of the status of high energy physics, described by a Standard Model — which still leaves too many questions unanswered to be the appropriate theory of elementary particles and their interactions.Following the Introduction are: three chapters which focus on the initial decade of operation, leading to the celebrated discovery of the Higgs Boson, on the techniques and physics of the luminosity upgrade, and finally on major options - of using the LHC in a concurrent, power economic, electron-hadron scattering mode, when upgraded to higher energies or eventually as an injector for the next big machine. The various technical and physics chapters, provided by 61 authors, characterise the fascinating opportunities the LHC offers for the next two decades ahead (possibly longer), with the goal to substantially advance our understanding of nature.
This dissertation focuses on the calculation of transport coefficients in the matter created in a relativistic heavy-ion collision after chemical freeze-out. This matter can be well approximated using a pion gas out of equilibrium. We describe the theoretical framework needed to obtain the shear and bulk viscosities, the thermal and electrical conductivities and the flavor diffusion coefficients of a meson gas at low temperatures. To describe the interactions of the degrees of freedom, we use effective field theories with chiral and heavy quark symmetries. We subsequently introduce the unitarization methods in order to obtain a scattering amplitude that satisfies the unitarity condition exactly, then go on to calculate the transport properties of the low-temperature phase of quantum chromodynamics - the hadronic medium - which can be used in hydrodynamic simulations of a relativistic heavy-ion collision and its subsequent evolution. We show that the shear viscosity over entropy density exhibits a minimum in a phase transition by studying this coefficient in atomic Argon (around the liquid-gas phase transition) and in the linear sigma model in the limit of a large number of scalar fields (which presents a chiral phase transition). Finally, we provide an experimental method for estimating the bulk viscosity in relativistic heavy-ion collisions by performing correlations of the fluctuating components of the stress-energy tensor.
This thesis presents the first measurement of charmed D0 meson production relative to the reaction plane in Pb–Pb collisions at the center-of-mass energy per nucleon-nucleon collision of √sNN = 2.76 TeV. It also showcases the measurement of the D0 production in p–Pb collisions at √sNN = 5.02 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement of the D0 azimuthal anisotropy with respect to the reaction plane indicates that low- momentum charm quarks participate in the collective expansion of the high-density, strongly interacting medium formed in ultra-relativistic heavy-ion collisions, despite their large mass. This behavior can be explained by charm hadronization via recombination with light quarks from the medium and collisional energy loss. The measurement of the D0 production in p–Pb collisions is crucial to separate the effect induced by cold nuclear matter from the final- state effects induced by the hot medium formed in Pb–Pb collisions. The D0 production in p–Pb collisions is consistent with the binary collision scaling of the production in pp collisions, demonstrating that the modification of the momentum distribution observed in Pb–Pb collisions with respect to pp is predominantly induced by final-state effects such as the charm energy loss.
This thesis presents theoretical and numerical studies on phenomenological description of the quark–gluon plasma (QGP), a many-body system of elementary particles. The author formulates a causal theory of hydrodynamics for systems with net charges from the law of increasing entropy and a momentum expansion method. The derived equation results can be applied not only to collider physics, but also to the early universe and ultra-cold atoms. The author also develops novel off-equilibrium hydrodynamic models for the longitudinal expansion of the QGP on the basis of these equations. Numerical estimations show that convection and entropy production during the hydrodynamic evolution are key to explaining excessive charged particle production, recently observed at the Large Hadron Collider. Furthermore, the analyses at finite baryon density indicate that the energy available for QGP production is larger than the amount conventionally assumed.
